Organic light-emitting display apparatus and method of manufactuing the same

ABSTRACT

Provided is an organic light-emitting display apparatus including a thin-film transistor (TFT) that includes an active layer, a gate electrode, and source/drain electrodes; an organic light-emitting device that includes a pixel electrode which is connected to the TFT, an intermediate layer which includes a light-emitting layer, and an opposite electrode; and an opposite electrode contact unit in which the opposite electrode is electrically connected to a power wiring, wherein, with regard to the power wiring, a surface that contacts the opposite electrode is formed to have an embossed structure.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a divisional application which claims priority under35 U.S.C. §120 from U.S. patent application Ser. No. 14/065,103, filedOct. 28, 2013, which claims priority to and the benefit of Korean PatentApplication No. 10-2013-0061255, filed on May 29, 2013, in the KoreanIntellectual Property Office, the disclosure of each of which isincorporated herein in its entirety by reference.

BACKGROUND

1. Field

One or more aspects of the present embodiments relate to an organiclight-emitting display apparatus, and more particularly, to an organiclight-emitting display apparatus in which a structure of an area, inwhich an opposite electrode that faces a pixel electrode contacts apower wiring, is improved.

2. Description of the Related Technology

Generally, an organic light-emitting display apparatus includes athin-film transistor (TFT) and an organic light-emitting device. Theorganic light-emitting display apparatus has a structure in which theorganic light-emitting device receives an appropriate driving signalfrom the TFT and emits light, thus displaying a desired image.

The TFT has a structure in which an active layer, a gate electrode, andsource/drain electrodes are stacked on a substrate. Accordingly, when acurrent is supplied to the gate electrode via a wiring that is formed onthe substrate, a current flows through the source/drain electrodes viathe active layer. At the same time, a current flows through a pixelelectrode of the organic light-emitting device that is connected to thesource/drain electrodes.

Additionally, the organic light-emitting device includes the pixelelectrode, the opposite electrode that faces the pixel electrode, and alight-emitting layer that is interposed therebetween. In such astructure, if a current flows through the pixel electrode via the TFT asdescribed above, a proper voltage is formed between the oppositeelectrode and the pixel electrode. Accordingly, light is emitted fromthe light-emitting layer, and thus an image is displayed.

In order to form a proper voltage in the light-emitting layer asdescribed above, the opposite electrode needs to be connected to thepower wiring so as to maintain a constant voltage. In this case, anopposite electrode contact unit, which is connected to the power wiring,may generate heat.

That is, the power wiring, which is generally connected to the oppositeelectrode, has a structure in which a plurality of wiring layers arestacked and one wiring layer, from among the plurality of wiring layers,is connected to the opposite electrode. The plurality of wiring layersmay be formed by stacking a gate electrode or a source electrode of theTFT, which are included in a display unit of the organic light-emittingdisplay apparatus. In a process of depositing an organic light-emittingmaterial on a pixel area in the display unit of the organiclight-emitting display apparatus, an organic light-emitting material isdeposited on a substrate that is separate from a deposition source for acertain distance. Thus, the organic light-emitting material may beunwantedly mixed into an opposite electrode contact unit, which is anon-display area of the organic light-emitting display apparatus. Inthis case, the organic light-emitting material, which is deposited onthe plurality of power wirings, may cause heat generation, and thus,resultantly cause a defect of a product.

Accordingly, in order to implement a more stable organic light-emittingdisplay apparatus, an improved structure, in which deposition of anorganic light-emitting material on the opposite electrode contact unitis prevented, is demanded.

SUMMARY

One or more aspects of the present embodiments provide an organiclight-emitting display apparatus in which one surface of a power wiringis formed to have an embossed structure, so that, even when an organicmaterial is mixed in an opposite electrode contact unit, an area inwhich the organic material is deposited on the power wiring isminimized.

According to an aspect of the present embodiments, there is provided anorganic light-emitting display apparatus including: a thin-filmtransistor (TFT) that includes an active layer, a gate electrode, asource electrode and a drain electrode; an organic light-emitting devicethat includes a pixel electrode which is connected to the TFT, anintermediate layer which includes a light-emitting layer, and anopposite electrode; and an opposite electrode contact unit in which theopposite electrode is electrically connected to a power wiring, wherein,with regard to the power wiring, a surface that contacts the oppositeelectrode is formed to have an embossed structure.

The power wiring may include at least one or more wiring layers, and theat least one or more wiring layers may include a wiring layer thatcomprises the same material and on the same layer as the source/drainelectrodes of the TFT.

The power wiring may include at least one or more wiring layers, and theat least one or more wiring layers may include a wiring layer thatcomprises a same material and on a same layer as the gate electrode ofthe TFT.

The one slope of the embossed structure may forms a specific angle withregard to a deposition source that deposits an intermediate layer of theorganic light-emitting device.

The specific angle may be determined so that a deposition material,which is generated from the deposition source, reaches the one slope ofthe embossed structure in a vertical direction.

The one slope of the embossed structure may be formed to be vertical tothe substrate of the organic light-emitting display apparatus.

The embossed structure may be formed in an engraving or embossingdirection with respect to the opposite electrode.

The gate electrode may include an upper gate electrode and a lower gateelectrode, and the lower gate electrode may be formed on a same layer asthe pixel electrode of the organic light-emitting device.

The power wiring may include first through third wiring layers, thefirst through third wiring layers are sequentially formed in a directiontoward the opposite electrode, the first wiring layer comprises a samematerial and on a same layer as the lower gate electrode, the secondwiring layer comprises the same material and on the same layer as thelower gate electrode, and the third wiring layer comprises the samematerial and on the same layer as the source electrode and the drainelectrode.

The pixel electrode, the lower gate electrode, or the first wiring layermay be formed to include one or more transparent metal oxides selectedfrom the group consisting of indium tin oxide (ITO), indium zinc oxide(IZO), zinc oxide (ZnO), and indium oxide (In₂O₃).

The upper gate electrode or the third wiring layer may include one ormore materials selected from the group consisting of silver (Ag),magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au),nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), lithium (Li),calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), molybdenumtungsten (MoW), and copper (Cu).

The opposite electrode contact unit may be formed in a non-display area.

The organic light-emitting display apparatus may further include aninterlayer insulating layer and a pixel-defining layer that are formedoutside outside a portion of the power wiring which is included in theopposite electrode contact unit.

The power wiring may be electrically connected to the opposite electrodevia a hole that is formed on the interlayer insulating layer and thepixel-defining layer.

The interlayer insulating layer may include an inorganic insulatingmaterial, and the pixel-defining layer may include an organic insulatingmaterial.

According to another aspect of the present embodiments, there isprovided method of manufacturing an organic light-emitting displayapparatus, the method including forming a first conductive layer and asecond conductive layer on a substrate; patterning the first conductivelayer and the second conductive layer to form a pixel electrode and afirst wiring layer of a power wiring from the first conductive layer,and to form a second wiring layer of the power wiring from the secondconductive layer; forming an interlayer insulating layer that includes ahole exposing a part of the pixel electrode and the second wiring layer;forming a third conductive layer on the interlayer insulating layer, andpatterning the third conductive layer to form a third wiring layer ofthe power wiring that has an embossed structure on an upper surface ofthe power wiring; forming a pixel-defining layer exposing a part of thepixel electrode and the third wiring layer of the power wiring; andforming an opposite electrode on the pixel-defining layer in a form of afront electrode, and which is electrically connected to the third wiringlayer of the power wiring.

The method includes, after the forming of the pixel-defining layer,depositing an intermediate layer, which includes a light-emitting layer,on the pixel electrode by using a deposition source, wherein one slopeof the embossed structure forms a specific angle with regard to thedeposition source.

The specific angle may be determined so that a deposition material,which is generated from the deposition source, reaches the one slope ofthe embossed structure in a vertical direction.

The one slope of the embossed structure may be formed to be vertical tothe substrate.

According to another aspect of the present embodiments, there isprovided an opposite electrode contact unit, including a power wiringthat includes at least one or more wiring layers; and an oppositeelectrode that is electrically connected to the power wiring, whereinthe opposite electrode contact unit is formed in a non-display area ofan organic light-emitting display apparatus, and the power wiring has anembossed structure on one surface thereof in a direction of the oppositeelectrode.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present embodimentswill become more apparent by describing in detail example embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a schematic plan view illustrating a structure of an organiclight-emitting display apparatus according to an embodiment;

FIG. 2 is a schematic cross-sectional view illustrating a part of anopposite electrode contact area of a conventional organic light-emittingdisplay apparatus;

FIGS. 3A through 3C are schematic diagrams for explaining a method ofdepositing an organic material on the organic light-emitting displayapparatus according to an embodiment;

FIG. 4 is a diagram illustrating the organic light-emitting displayapparatus according to an embodiment;

FIGS. 5A through 5F are diagrams illustrating a method of manufacturingthe organic light-emitting display apparatus of FIG. 3, according to anembodiment;

FIG. 6 is a diagram illustrating an organic light-emitting displayapparatus 1 according to another embodiment; and

FIG. 7 is a diagram illustrating the organic light-emitting displayapparatus 1 according to another embodiment.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that show, by way of illustration, specificembodiments in which the embodiments may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the embodiments. It is to be understood that the variousembodiments, although different, are not necessarily mutually exclusive.For example, a particular feature, structure, or characteristicdescribed herein, in connection with one embodiment, may be implementedwithin other embodiments without departing from the spirit and scope ofthe embodiments. In addition, it is to be understood that a location orarrangement of individual elements within each disclosed embodiment maybe modified without departing from the spirit and scope of theembodiments. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present embodiments isdefined only by the appended claims, appropriately interpreted, alongwith the full range of equivalents to which the claims are entitled. Inthe drawings, like numerals refer to elements having the same or similarfunctionality throughout the several views.

The present embodiments will now be described more fully with referenceto the accompanying drawings, in which exemplary embodiments are shown.

FIG. 1 is a schematic plan view illustrating a structure of an organiclight-emitting display apparatus 1 according to an embodiment.

The organic light-emitting display apparatus 1 includes a display area110 in which a plurality of pixels are arranged on a substrate 10, and anon-display area 120 that is formed outside of the display area 110.

The substrate 10 may be a low-temperature poly-crystalline silicon(LTPS) substrate, a glass substrate, or a plastic substrate.

In the display area 110, a pixel (not shown), which forms a basic unitof a displayed image, is arranged in the form of matrix, and a wiring,which is electrically connected to each pixel, is formed. A pixel mayinclude a pixel circuit, which includes at least one thin-filmtransistor (TFT) and a capacitor, and an organic light-emitting deviceEL. The organic light-emitting device EL has a structure in which apixel electrode that is an anode electrode and is connected to the TFT,an organic emissive layer, and an opposite electrode that is a cathodeelectrode and is in the form of a front electrode are stacked. A cathodevoltage is applied to each pixel via the opposite electrode.

The non-display area 120 may include an opposite electrode contact area130 that is electrically connected to the opposite electrode (59, seeFIG. 2) in the display area 110 via an opposite electrode contact unitCNT, and a pad area 140 in which a pad PAD (not shown) via which poweris applied to the display area 110 and the opposite electrode contactarea 130 is formed. The opposite electrode contact area 130 applies acathode voltage, which is applied from the outside via the oppositeelectrode contact unit CNT, to each pixel via the pad PAD. One or moreopposite electrode cathode areas 130 and pad areas 140 may be formed onat least one side of the non-display area 120. FIG. 1 illustrates anexample in which the opposite electrode cathode area 130 and the padarea 140 are respectively formed on upper and lower parts of thenon-display area 120. However, the present embodiments are not limitedthereto. One or more opposite electrode contact units CNT may be formedin the opposite electrode cathode area 130.

According to an embodiment, an upper surface of a power wiring 30 (seeFIGS. 4 through 6), which is included in the opposite electrode contactunit CNT, is formed to have an embossed structure. Thus, a resistanceincrease and heat generation, which may be caused by unintentionalmixing of an organic material into the opposite electrode contactregion, may be prevented.

The substrate 10 may be bonded to an encapsulation substrate (notillustrated), which faces the substrate 100, by using a sealing member(not illustrated) that is formed on the non-display area 120. Althoughnot illustrated, the sealing member is formed on the substrate 10 so asto seal a light-emitting area. Thus, the light-emitting area may beprotected from external air. For example, the sealing film may have afilm growth structure formed by alternating a film consisting of aninorganic material such as silicon oxide or silicon nitride and a filmconsisting of an organic material such as epoxy or polyimide. As anotherexample, the sealing film may include a film formed of low-melting glasssuch as tin oxide (SnO). However, this is only an example. The sealingfilm is not limited thereto, and any thin film with a sealing structuremay be used as the sealing film.

FIG. 2 is a schematic cross-sectional view illustrating a part of anopposite electrode contact area of a conventional organic light-emittingdisplay apparatus.

Referring to FIG. 2, with respect to an opposite electrode contact areaincluded in the conventional organic light-emitting display apparatus, abuffer layer 11 is formed on the substrate 10, and a power wiring 56 isformed on the buffer layer 11. The opposite electrode 59 is formed onthe power wiring 56. In this case, an organic material 58 may beunintentionally mixed between the power wiring 56 and the oppositeelectrode 59. In a process of forming the organic emissive layer in apixel area, the organic material 58 may be unintentionally mixed intothe opposite electrode contact unit. Then, an area in which the powerwiring 56 directly contacts the opposite electrode 59 may be reduced,and thus, resistance therein may be increased. A problem of mixing ofthe organic material 58 may occur when an in-line deposition method,which may be desirably used for manufacturing a large organiclight-emitting diode (OLED) panel, is used. This may increase resistancein an opposite electrode contact unit, and thus, generate heat.

FIGS. 3A through 3C are schematic diagrams for explaining a method ofdepositing an organic material on the organic light-emitting displayapparatus according to an embodiment.

FIG. 3A is a diagram illustrating a location in which, when an organicmaterial is deposited, a blade BLADE is formed on the substrate 10. Theorganic material may be formed only in the display area 110.Accordingly, as shown in FIG. 3A, the blade BLADE is formed in a regioncovering the opposite electrode contact area 130 and the pad area 140,so that the organic material is not deposited in the opposite electrodecontact area 130 and the pad area 140, which are in the non-display area120. When a deposition material which is generated from a depositionsource, that is, an organic material is formed on the substrate 10, theblade BLADE functions to prevent the organic material from being formedin the non-display area 120. A mask may be used, instead of the bladeBLADE.

FIG. 3B is a diagram illustrating a reason why an organic material isdeposited in the opposite electrode contact area 130, in spite of theuse of the blade BLADE.

A deposition source SOURCE deposits a deposition material by using atool such as a blade or a mask to distinguish a deposition area from anon-deposition area. In an example shown in FIG. 3B, an area b, which iscovered by the blade BLADE, is a non-deposition area, and an area a,which is not covered by the blade BLADE, is a deposition area. It isassumed that a deposition material is sprayed from areas d1 and d2 ofthe deposition source SOURCE. Since the organic light-emitting displayapparatus 1 is kept away from the blade BLADE by a distance Z.Accordingly, the deposition source SOURCE deposits an organic materialwhen the deposition source SOURCE is separate from the substrate 10 bydistances Z and TS, thus forming an intermediate layer 48 in the organiclight-emitting device EL that will be described later. However, at thesame time, the deposition source SOURCE also deposits the depositionmaterial in the non-deposition area b, even when the blade BLADE isformed on the substrate 10. This is because the blade BLADE is kept awayfrom the organic light-emitting display apparatus 1 by a certaindistance. In an example shown in FIG. 3B, the deposition material may beunintentionally mixed into an area expressed by the equationb=(d1*Z)/TS.

FIG. 3C is a diagram illustrating a method of reducing an area in whicha deposition material is mixed in the organic light-emitting displayapparatus 1, according to an embodiment.

With regard to the organic light-emitting display apparatus 1 accordingto an embodiment, an embossed structure may be formed as shown in FIG.3C. An angle between the deposition source SOURCE and an end of theblade BLADE is θ1 in the example shown in FIG. 3B. Then, according to anembodiment, an angle between the organic light-emitting displayapparatus 1 and one slope of the embossed structure may be θ1. In such acase, a deposition material is not deposited on the other slope of theembossed structure of the organic light-emitting display apparatus 1.FIGS. 3B and 3C schematically illustrate a case in which a depositionmaterial is mixed in the organic light-emitting display apparatus 1,accurately, FIGS. 3B and 3C illustrate a case in which a depositionmaterial is mixed into the power wiring 30 of the cathode contact unitCNT. According to an embodiment, the power wiring 30 is formed to havean embossed structure (to be shown in FIGS. 4 through 6). Accordingly, aproblem of heat generation may be solved by increasing an area in whichthe power wiring 30, which will be described later, directly contactsthe opposite electrode 19.

FIG. 4 is a diagram illustrating the organic light-emitting displayapparatus according to an embodiment.

Referring to FIG. 4, according to an embodiment, an upper surface of thepower wiring 30 of the opposite electrode contact unit CNT, included inthe organic light-emitting display apparatus 1, is formed to have anembossed structure.

The organic light-emitting display apparatus 1 in the current embodimentincludes the TFT, the organic-light emitting device EL, and the oppositeelectrode contact unit CNT in which the opposite electrode of theorganic light-emitting device EL is connected to the power wiring 30.

The TFT consists of an active layer 21, a gate electrode 20, andsource/drain electrodes 26 s and 26 d. The gate electrode 20 consists ofa lower gate electrode 23 and an upper gate electrode 24. The lower gateelectrode 23 comprises a transparent conductive material. The upper gateelectrode 24 comprises metal. A gate insulating layer 12 is interposedbetween the gate electrode 20 and the active layer 21 so as to insulatethe gate electrode 20 from the active layer 21. Additionally,source/drain areas, which have an electrical conductivity, are formed atboth edges of the active layer 21, and are connected to the source/drainelectrodes 26 s and 26 d.

The organic light-emitting device EL consists of a pixel electrode 43that is electrically connected to one of the source/drain electrodes 26s and 26 d of the TFT, the opposite electrode 19 that functions as acathode, and the organic intermediate layer 48 that is interposedbetween the pixel electrode 43 and the opposite electrode 19. Areference numeral 15 refers to an interlayer insulating layer(hereinafter referred to as a first insulating layer), and a referencenumeral 17 refers to a pixel-defining layer (hereinafter referred to asa second insulating layer).

Additionally, the opposite electrode contact unit CNT includes a firstwiring layer 33, a second wiring layer 34, and a third wiring layer 36,as the power wiring 30 that contacts the opposite electrode 19. Thefirst wiring layer 33 and the second wiring layer 34 comprise the samematerial and on the same respective layers as the lower gate electrode23 and the upper gate electrode 24. The third wiring layer 36 comprisesthe same material and on the same layer as the source/drain electrodes26 s and 26 d. Otherwise, according to another embodiment, a wiringlayer of the power wiring 30 may comprise the same material and on thesame layer as the gate electrode 20.

Referring to the embodiment shown in FIG. 4, the first insulating layer15 is formed outside the power wiring 30, so as to be separate from thepower wiring 30 with a space therebetween. The second insulating layer17 is formed to fill the space between the power wiring 30 and the firstinsulating layer 15, and is formed to be interposed between the thirdwiring layer 36 and the opposite electrode 19. In FIG. 4, the secondinsulating layer 17 is formed to fill holes of a certain depth that areformed in) the gate insulating layer 12 and the buffer layer 11 on thesubstrate 10. However, the second insulating layer 17 is not limitedthereto, and may be formed to fill only an upper part of the gateinsulating layer 12. Additionally, according to the embodiment shown inFIG. 4, the first insulating layer 15 is illustrated to be separate fromthe power wiring 30. However, a space may not be provided between thefirst insulating layer 15 and the power wiring 30. Additionally, unlikethe illustration in FIG. 4, the third wiring layer 36 may not cover endsof the first and second wiring layers 33 and 34, and may be formed onlyon an upper part of the first and second wiring layers 33 and 34.

According to an embodiment with reference to FIG. 4, since the thirdwiring layer 36 is formed to have an embossed structure, an organicmaterial 38 is deposited only on one slope of the embossed structure.The organic material 38 may be a material that is deposited when theintermediate layer 48 is formed in the organic light-emitting device ELby using a deposition source. As described in detail with respect toFIG. 3C, the organic material 38 is deposited only on a surface thatfaces the deposition source SOURCE, in the embossed structure of thethird wiring layer 36. Accordingly, compared to the opposite electrodecontact unit CNT of the conventional organic light-emitting displayapparatus, an area in which the third wiring layer 36 directly contactsthe opposite electrode 19 is increased, and thus, heating resistance maybe reduced.

More specifically, when the embossed structure is formed as illustratedin FIG. 3C, the deposition source SOURCE deposits a deposition materialwith a certain incident angle. Thus, the deposition material may beformed on only one slope of the embossed structure. That is, asillustrated in FIG. 3C, when a deposition material is deposited on thesubstrate 10 with an angle of θ1 from one end of the deposition sourceSOURCE, if an angle between one slope of the embossed structure and thesubstrate 10 is θ1, a deposition angle and an angle of a slope at oneend of the third wiring layer 36 are perpendicular in direction to eachother. Accordingly, a deposition material is deposited only on one slopeof the embossed structure of the third wiring layer 36, and thedeposition material may not be deposited on the other slope of theembossed structure. Therefore, an area in which the organic material 38,which is the deposition material, is deposited may be minimized, andthus an amount of generated heat may be reduced.

In the embodiment shown in FIG. 4, only an upper surface of the thirdwiring layer 36, from among the power wiring 30, is illustrated to havean embossed structure. However, according to another embodiment, theorganic light-emitting display apparatus 1 may be formed so that allwiring layers of the power wiring 30 may respectively have an embossedshape. For example, unlike the embodiment shown in FIG. 4, in which onlythe third wiring layer 36 has an embossed shape, the first wiring layer33, the second wiring layer 34, and the third wiring layer 36 may beformed to have an embossed shape. That is, with regard to the organiclight-emitting display apparatus 1 in the present embodiments, some orall layers of the power wiring 30 may have an embossed shape.Resultantly, an upper surface of the power wiring 30 in a directiontowards the opposite electrode 19 may have an embossed shape.Accordingly, even when the organic material 38 is mixed into the organiclight-emitting display apparatus 1, the organic material 38 is depositedonly on some slopes of the power wiring 30, and thus, heating resistancemay be reduced.

FIGS. 5A through 5F are diagrams illustrating a method of manufacturingthe organic light-emitting display apparatus of FIG. 4, according to anembodiment.

Referring to FIG. 5A, the buffer layer 11 is formed on the substrate 10so as to maintain a smoothness of the substrate 10 and preventpenetration of an impure element into the substrate 10.

The substrate 10 may comprise transparent glass having silicon dioxide(SiO₂) as a main component. However, the substrate 10 is not limitedthereto, and may comprise various materials, such as transparentplastic, metal, and the like.

The active layer 21 of the TFT is formed on the buffer layer 11. Theactive layer 21 may comprise a polycrystalline silicon material, and ispatterned by using a mask process. A material of the active layer 21 isnot limited to silicon, and the active layer 21 may comprise an oxidesemiconductor. For example, the active layer 21 may comprise agalium-indium-zinc-oxide (G-I—Z—O) layer [(In₂O₃)a(Ga₂O₃)b(ZnO)c layer],where a, b, and c are real numbers, and a≧0, b≧0, and c<0. If the activelayer 21 comprises an oxide semiconductor, a doping process, which willbe explained hereinafter, may be omitted.

Then, the gate insulating layer 12 is formed on the patterned activelayer 21. The gate insulating layer 12 may be formed by depositing aninorganic insulating layer such as silicon nitride (SiN_(x)) or siliconoxide (SiO_(x)) by using a method such as plasma-enhanced chemical vapordeposition (PECVD), atmospheric pressure chemical vapor deposition(APCVD), or low pressure CVD (LPCVD).

Then, as illustrated in FIG. 5B, a first conductive layer (notillustrated) and a second conductive layer (not illustrated) aresequentially deposited on the gate insulating layer 12. Then, the pixelelectrode 43 and the auxiliary electrode 44 of the organiclight-emitting device EL, the gate electrode 20 of the TFT, and thefirst wiring layer 33 and the second wiring layer 34 that form a part ofthe power wiring 30, which is included in the opposite electrode contactunit CNT, are patterned.

The first conductive layer (not illustrated) is patterned into the pixelelectrode 43 of the organic light-emitting device EL, the lower gateelectrode 23 of the TFT, and the first wiring layer 33 of the powerwiring 30. The first conductive layer may include at least one materialselected from the group consisting of transparent materials such asindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), andindium oxide (In₂O₃).

The second conductive layer (not illustrated) is patterned into theauxiliary electrode 44 of the organic light-emitting device EL, theupper gate electrode 24 of the TFT, and the second wiring layer 34 ofthe power wiring 30. The second conductive layer may include at leastone material selected from silver (Ag), magnesium (Mg), aluminum (Al),platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd),iridium (Ir), chrome (Cr), lithium (Li), calcium (Ca), molybdenum (Mo),titanium (Ti), tungsten (W), molybdenum tungsten (MoW), andaluminum/copper (Al/Cu).

The gate electrode 20 is formed at a location which corresponds to acenter of the active layer 21. The active layer 21 is doped with ann-type or p-type impurity by using the gate electrode 20 as a mask.Then, a channel unit is formed in an area of the active layer 21 that iscovered by the gate electrode 20, and source/drain units are formed inthe other area of the active layer 21 that is not covered by the gateelectrode 20.

Then, referring to FIG. 5C, the first insulating layer 15 is depositedon an entire surface of the substrate 10, and holes H1 through H5 areformed by using a mask process.

The first insulating layer 15 may be formed by employing a spin coatingmethod using at least one material selected from the group consisting oforganic insulating materials such as polyimide, polyamide, acryl resin,benzo-cyclo-butene (BCB), and phenolic resin. The first insulating layer15 is formed to have a greater thickness than that of the gateinsulating layer 12, thus functioning as an interlayer insulating layerbetween the gate electrode 20 and the source/drain electrodes 26 s and26 d of the TFT. The first insulating layer 15 may be formed by using aninorganic insulating material, similar to the gate insulating layer 12,as well as the organic insulating material described above. The firstinsulating layer 15 may also be formed by alternating the organicinsulating material and the inorganic insulating material.

The first insulating layer 15 is patterned to form the first hole H1exposing a partial area of the pixel electrode 43 of the organiclight-emitting device EL, the second hole H2 exposing a partial area ofthe auxiliary electrode 44, the third and fourth holes H3 and H4exposing the active layer 21 of the TFT, and the fifth hole H5 exposinga partial or entire area of the power wiring 30 of the oppositeelectrode contact unit CNT. A periphery of the first wiring layer 33 andthe second wiring layer 34 may be etched and carved to a certain depthof the gate insulating layer 12 and the buffer layer 11, and a space maybe provided between the first wiring layer 33, the second wiring layer34, and the first insulating layer 15. Otherwise, the presentembodiments are not limited to the example shown in FIG. 5C, and thefirst insulating layer 15 may be etched so that a space is not providedbetween the first wiring layer 33, the second wiring layer 34, and thefirst insulating layer 15.

Then, referring to FIG. 5D, a third conductive layer (not illustrated)is deposited and patterned on an entire surface of the substrate 10 onthe first insulating layer 15, thereby forming the source/drainelectrodes 26 s and 26 d of the TFT and the third wiring layer 36 of thepower wiring 30. The third conductive layer may be formed by using thesame material selected from among the same conductive materials used forforming the first and second conductive layers, or formed of Mo/Al/Mo.The source/drain electrodes 26 s and 26 d and the third wiring layer 36are formed by patterning the third conductive layer. The third wiringlayer 36 is formed to cover ends of the first wiring layer 33 and thesecond wiring layer 34. Otherwise, the third wiring layer 36 may beformed on the second wiring layer 34, so as not to cover ends of thesecond wiring layer 34. Additionally, the auxiliary electrode 44 isetched to expose the pixel electrode 43. The electrode 26, which is oneof the source/drain electrodes 26 s and 26 d, is connected to theauxiliary electrode 44.

According to an embodiment, the third wiring layer 36 may be formed tohave an embossed structure so that an upper part of the power wiring 30has an embossed structure. In order to form the third wiring layer 36 tohave an embossed structure, a slit mask or a half-tone mask may be usedas a mask for patterning the third conductive mask.

Then, referring to FIG. 5E, the second insulating layer 17 is formed onthe substrate 10. The second insulating layer 17 may be formed byemploying a spin coating method using at least one material selectedfrom the group consisting of organic insulating materials such aspolyimide, polyamide, acryl resin, BCB, and phenolic resin.

By patterning the second insulating layer 17, holes H6 and H7respectively exposing a center unit of the pixel electrode 43 and thethird wiring layer 36 are formed.

Then, as illustrated in FIG. 5F, the intermediate layer 48, whichincludes an emissive layer (EML), is formed in the hole H5 that exposesthe pixel electrode 43. As described with regard to FIG. 3, in a processof forming the intermediate layer 48, the organic material 38 may bealso deposited in the opposite electrode contact unit CNT.

The intermediate layer 48 may be formed by stacking one or more layersfrom among functional layers such as the EML, a hole transport layer(HTL), a hole injection layer (HIL), an electron transport layer (ETL),and an electron injection layer (EIL) to form a structure of a single ormultiple layers.

The EML may include a low-molecular weight organic material or a polymerorganic material. When the EML comprises a low-molecular weight organicmaterial, the EML may be formed by stacking the HTL and the HIL in adirection from the EML to the pixel electrode 43 and stacking the ETLand the EIL in a direction from the EML to the opposite electrode 19.Besides, other layers may be stacked as desired. Other organic materialssuch as copper phthalocyanine (CuPc),N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), andtris-8-hydroxyquinoline aluminum (Alq3) may be used.

In the case of the polymer EML that comprises a polymer organicmaterial, the polymer EML includes only the HTL in addition to the EML.The HTL may be formed on the pixel electrode 43 by employing an ink jetprinting method or a spin-coating method usingpoly-(2,4)-ethylene-dihydroxy thiophene (PEDOT) or polyaniline (PANI).The polymer EML may be formed by using polyphenylene vinylene (PPV),cyano-PPV, or polyfluorene.

In the embodiment described above, the intermediate layer 48 is formedin the hole H6, and an additional fluorescent material is formed foreach pixel. However, the present embodiments are not limited thereto.The intermediate layer 48 may be formed on the entire second insulatinglayer 17 inside the display area 110, regardless of a location of thepixel. The EML may be formed, for example, by vertically stacking ormixing layers that include light-emitting materials which respectivelyemit red, green, and blue light. If white light can be emitted, othercolors can be combined. Additionally, a color conversion layer thatconverts the emitted white light into a predetermined color, or a colorfilter may be further included.

Then, the opposite electrode 19 is formed entirely on the substrate 10.When the organic light-emitting display apparatus 1 is a bottom-emissiontype display apparatus which displays an image in a direction towardsthe substrate 10, the pixel electrode 43 may be a transparent electrode,and the opposite electrode 19 may be a reflective electrode. Thereflective electrode may be formed by thinly depositing metal having alow work function, for example, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr,Li, Ca, LiF/Ca, LiF/Al, or a combination thereof.

Conversely, when the organic light-emitting display apparatus 1 is atop-emission type display apparatus which emits light in an oppositedirection to the substrate, the pixel electrode 43 is a light reflectiveelectrode and the opposite electrode is a light transmissive electrode.In this case, the pixel electrode 43 may further include a reflectivelayer formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, ytterbium(Yb) or Ca. Then, the opposite electrode may be formed to include atransparent metal oxide such as ITO, IZO, ZnO, or In₂O₃ so as to allowlight transmission. The opposite electrode may also comprise a thin filmby using metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, orCa.

The opposite electrode 19 is deposited on an entire surface of thesubstrate 10, and connected to the third wiring layer 36 of the powerwiring 30 via the hole H7. According to an embodiment, an upper part ofthe power wiring 30 has an embossed structure. Accordingly, even whenthe organic material 36 is unintentionally mixed, the organic material38 may be formed only on a partial slope of the third wiring layer 36.Thus, an area in which the power wiring 30 and the opposite electrode 19contact each other may be increased. Additionally, since the area inwhich the power wiring 30 and the opposite electrode 19 contact eachother is increased, an area of the opposite electrode contact area 130and the non-display area 120 may be reduced.

Additionally, according to other embodiments, a shape of an embossedstructure of the power wiring 30 may be variously formed.

FIG. 6 is a diagram illustrating the organic light-emitting displayapparatus 1 according to another embodiment.

Referring to FIG. 6, unlike the embodiment shown in FIG. 4, one slope ofthe power wiring 30 is vertical to the substrate 10. In this case, theorganic material 38 is deposited only on the slope that is vertical tothe substrate 10. Thus, an area in which the opposite electrode 19 andthe power wiring 30 contact each other may be increased.

FIG. 7 is a diagram illustrating the organic light-emitting displayapparatus 1 according to another embodiment.

Referring to FIG. 7, unlike the embodiment shown in FIG. 4, an upperpart of the power wiring 30 is formed to have an embossed structure inthe engraved form.

According to the present embodiments, an area in which a power wiringand an opposite electrode contact each other is increased, and thus,ignition or deterioration, which may be caused by heat generation, maybe prevented.

The particular implementations shown and described herein areillustrative examples of the embodiments and are not intended tootherwise limit the scope of the embodiments in any way. For the sake ofbrevity, conventional electronics, control systems, software developmentand other functional aspects of the systems (and components of theindividual operating components of the systems) may not be described indetail. Furthermore, the connecting lines, or connectors shown in thevarious figures presented are intended to represent example functionalrelationships and/or physical or logical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships, physical connections or logical connectionsmay be present in a practical device. Moreover, no item or component isessential to the practice of the embodiments unless the element isspecifically described as “essential” or “critical”.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the embodiments (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural. Furthermore, recitation of ranges of values herein are merelyintended to function as a shorthand method of referring individually toeach separate value falling within the range, unless otherwise indicatedherein, and each separate value is incorporated into the specificationas if it were individually recited herein. Finally, the steps of allmethods described herein can be performed in any suitable order unlessotherwise indicated herein or otherwise clearly contradicted by context.The use of any and all examples, or language (e.g., “such as”) providedherein, is intended merely to better illuminate the embodiments and doesnot pose a limitation on the scope of the embodiments unless otherwiseclaimed. Additionally, it is to be appreciated that all changes,equivalents, and substitutes that do not depart from the spirit andtechnical scope of the present embodiments are encompassed in thepresent embodiments according to design conditions and factors.

The present embodiments have been described more fully with reference tothe accompanying drawings, in which example embodiments are shown. Theembodiments may, however, be embodied in many different forms and shouldnot be construed as being limited to the embodiments set forth herein.It will be understood by those skilled in the art that various changesin form and details may be made therein without departing from thespirit and scope of the embodiments as defined by the appended claims.

Therefore, the scope of the embodiments is defined not by the detaileddescription of the embodiments but by the appended claims, and alldifferences within the scope will be construed as being included in thepresent embodiments.

What is claimed is:
 1. A method of manufacturing an organic light-emitting display apparatus, the method comprising: forming a first conductive layer and a second conductive layer on a substrate; patterning the first conductive layer and the second conductive layer to form a pixel electrode and a first wiring layer of a power wiring from the first conductive layer, and to form a second wiring layer of the power wiring from the second conductive layer; forming an interlayer insulating layer that comprises a hole exposing a part of the pixel electrode and the second wiring layer; forming a third conductive layer on the interlayer insulating layer, and patterning the third conductive layer to form a third wiring layer of the power wiring that has an embossed structure on an upper surface of the power wiring; forming a pixel-defining layer exposing a part of the pixel electrode and the third wiring layer of the power wiring; and forming an opposite electrode on the pixel-defining layer in the form of a front electrode, which is electrically connected to the third wiring layer of the power wiring.
 2. The method of claim 1, further comprising, after the forming of the pixel-defining layer, depositing an intermediate layer, which comprises a light-emitting layer, on the pixel electrode using a deposition source, wherein one slope of the embossed structure forms a specific angle with regard to the deposition source.
 3. The method of claim 2, wherein the specific angle is determined so that a deposition material, which is generated from the deposition source, reaches the one slope of the embossed structure in a vertical direction.
 4. The method of claim 2, wherein the one slope of the embossed structure is formed to be vertical to the substrate. 